Fixtures link together, regardless of length, to a maximum of 8 units up to 36in fixtures and 6 units up to 48in fixtures. Used as supplemental overhead and side lighting, as well as additional light for tall plants when hung vertically, their slim design allows them to fit virtually anywhere you need additional light. Cost effective to operate, easy to install and uses minimal watts per lamp with a long lamp life of over 10,000 hours. Complete kit includes: electronic ballast, NanoTech reflector, 6400K lamp, power cord, jumper plug and mounting clips.